Systems and methods for configuring and communicating with HVAC devices

ABSTRACT

An actuator in a HVAC system includes a mechanical transducer, an input data connection, a feedback data connection, and a processing circuit. The processing circuit is configured to use a master-slave detection signal communicated via the feedback data connection to select an operating mode for the actuator from a set of multiple potential operating modes including a master operating mode and a slave operating mode. The processing circuit is configured to operate the mechanical transducer in response to a control signal received via the input data connection according to the selected operating mode.

BACKGROUND

The present disclosure relates generally to the field of control equipment such as actuators, sensors, controllers, and other types of devices that can be used for monitoring or controlling an automated system or process. The present disclosure relates more particularly to systems and methods for configuring and communicating with control equipment in a building automation system.

A building automation system (BAS) is, in general, a system of devices configured to control, monitor, and manage equipment in or around a building or building area. A BAS can include a heating, ventilation, and air conditioning (HVAC) system, a security system, a lighting system, a fire alerting system, another system that is capable of managing building functions or devices, or any combination thereof. BAS devices may be installed in any environment (e.g., an indoor area or an outdoor area) and the environment may include any number of buildings, spaces, zones, rooms, or areas. A BAS may include METASYS building controllers or other devices sold by Johnson Controls, Inc., as well as building devices and components from other sources.

A BAS may include one or more computer systems (e.g., servers, BAS controllers, etc.) that serve as enterprise level controllers, application or data servers, head nodes, master controllers, or field controllers for the BAS. Such computer systems may communicate with multiple downstream building systems or subsystems (e.g., an HVAC system, a security system, etc.) according to like or disparate protocols (e.g., LON, BACnet, etc.). The computer systems may also provide one or more human-machine interfaces or client interfaces (e.g., graphical user interfaces, reporting interfaces, text-based computer interfaces, client-facing web services, web servers that provide pages to web clients, etc.) for controlling, viewing, or otherwise interacting with the BAS, its subsystems, and devices. A BAS may include various types of controllable equipment (e.g., chillers, boilers, air handling units, dampers, motors, actuators, pumps, fans, etc.) that can be used to achieve a desired environment, state, or condition within a controlled space.

In some BAS implementations, it may be desirable to arrange two or more actuators in tandem (e.g., in a master-slave configuration). Conventional actuators generally include a physical switch (e.g., a detent potentiometer) attached to the actuator for configuring the actuator to operate as either the master or the slave in a master-slave configuration. It can be challenging to properly configure tandem-mounted actuators, especially when access to the actuators is restricted or when the proper master-slave configuration is unclear.

Other types of control equipment also generally require physical access to the equipment for various activities such as commissioning, programming, setting addresses, installing firmware, performing diagnostics, and/or reading a current operating status. For example, physical access to the circuit board of a control device may be required to program the device. It can be difficult to access control devices that are mounted in a confined space or sealed from the external environment.

SUMMARY

One implementation of the present disclosure is an actuator in a HVAC system. The actuator includes a mechanical transducer, an input data connection, a feedback data connection, and a processing circuit. The processing circuit is configured to use a master-slave detection signal communicated via the feedback data connection to select an operating mode for the actuator from a set of multiple potential operating modes including a master operating mode and a slave operating mode. The processing circuit is configured to operate the mechanical transducer in response to a control signal received via the input data connection according to the selected operating mode.

In some embodiments, the processing circuit is configured to generate the master-slave detection signal and to output the master-slave detection signal via the feedback data connection.

In some embodiments, the processing circuit is configured to monitor the feedback data connection for a reply signal from another actuator. The reply signal may be generated by the other actuator in response to receiving the output master-slave detection signal. The processing circuit may be configured to select the master operating mode in response to detecting the reply signal from the other actuator at the feedback data connection.

In some embodiments, the processing circuit is configured to monitor the input data connection for the master-slave detection signal. The master-slave detection signal may be generated by another actuator. The processing circuit may be configured to select the slave operating mode in response to detecting the master-slave detection signal from the other actuator at the input data connection.

In some embodiments, the processing circuit is configured to generate a reply signal in response to detecting the master-slave detection signal at the input data connection. The processing circuit may be configured to output the reply signal via the input data connection.

In some embodiments, the processing circuit is configured to monitor the input data connection for the master-slave detection signal and to monitor the feedback data connection for a reply signal. The processing circuit may be configured to select a normal operating mode in response to a determination that the master-slave detection signal is not detected at the input data connection and the reply signal is not detected at the feedback data connection.

In some embodiments, the processing circuit is configured to engage in bi-directional communications with another actuator via the feedback data connection. The feedback data connection may be connected with an input data connection of the other actuator.

In some embodiments, the processing circuit is configured to engage in bi-directional communications with another actuator via the input data connection. The input data connection may be connected with a feedback data connection of the other actuator.

In some embodiments, the actuator further includes memory storing instructions for generating the master-slave detection signal. The processing circuit may generate the master-slave detection signal according to the stored instructions. In some embodiments, the master-slave detection signal includes a series of digital pulses.

In some embodiments, the processing circuit includes a master detection circuit configured to monitor the input data connection for the master-slave detection signal, to generate a reply signal in response to detecting the master-slave detection signal at the input data connection, and to output the reply signal via the input data connection. In some embodiments, the processing circuit includes a slave detection circuit configured to generate the master-slave detection signal, to output the master-slave detection signal via the feedback data connection, and to monitor the feedback data connection for the reply signal.

Another implementation of the present disclosure is an actuator in a HVAC system. The actuator includes a mechanical transducer and a processing circuit having a processor and memory. The processing circuit is configured to operate the mechanical transducer according to a control program stored in the memory. The actuator further includes a wireless transceiver configured to facilitate bidirectional wireless data communications between the processing circuit and an external device. The actuator further includes a power circuit configured to draw power from a wireless signal received via the wireless transceiver and to power the processing circuit and the wireless transceiver using the drawn power. The processing circuit is configured to use the power drawn from the wireless signal to wirelessly transmit data stored in the memory of the actuator to the external device via the wireless transceiver, to wirelessly receive data from the external device via the wireless transceiver, and to store the data received from the external device in the memory of the actuator.

In some embodiments, the external device is a mobile device. The bidirectional wireless data communications between the processing circuit and the external device may include direct communications between the wireless transceiver of the actuator and a wireless transceiver of the mobile device.

In some embodiments, the processing circuit is configured to wirelessly exchange data with the external device without requiring any wired power or data connections to the actuator. In some embodiments, the processing circuit is configured to wirelessly exchange data with the external device while the actuator is contained within packaging that prevents physical access to the actuator.

In some embodiments, the data received from the external device includes firmware for the actuator. The firmware may include the control program used by the processing circuit to operate the mechanical transducer. The control program may include logic for operating the mechanical transducer based on variable configuration parameters separate from the control program.

In some embodiments, at least one of the data transmitted to the external device and the data received from the external device include configuration parameters for the actuator.

In some embodiments, the processing circuit is capable of operating multiple different actuator models. The data received from the external device may include model identification parameters identifying a particular actuator model and defining configuration settings specific to the identified actuator model. The processing circuit may use the model identification parameters to operate the actuator according to configuration settings specific to the identified actuator model.

In some embodiments, the processing circuit is configured to perform an actuator diagnostic test and to generate diagnostic information as a result of the test. The data transmitted to the external device may include the diagnostic information generated by the processing circuit.

In some embodiments, the external device is another actuator and at least one of the data transmitted to the external device and the data received from the external device include a master-slave detection signal. The processing circuit may be configured to use the master-slave detection signal to select an operating mode for the actuator from a set of multiple potential operating modes including a master operating mode and a slave operating mode

Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined solely by the claims, will become apparent in the detailed description set forth herein and taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a building serviced by a HVAC system, according to an exemplary embodiment.

FIG. 2 is a block diagram illustrating a portion of the HVAC system of FIG. 1 in greater detail, according to an exemplary embodiment.

FIG. 3 is a block diagram illustrating multiple actuators of the HVAC system of FIG. 1 arranged in tandem, according to an exemplary embodiment.

FIG. 4 is a block diagram illustrating the actuators of FIG. 3 in greater detail, according to an exemplary embodiment.

FIG. 5 is a block diagram illustrating a first process for automatically detecting an actuator arrangement and setting an actuator operating mode in which a master actuator initiates the process, according to an exemplary embodiment.

FIG. 6 is a block diagram illustrating a second process for automatically detecting an actuator arrangement and setting an actuator operating mode in which a slave actuator initiates the process, according to an exemplary embodiment.

FIG. 7A is a block diagram illustrating the master actuator and slave actuator of FIGS. 3-5 in greater detail, according to an exemplary embodiment.

FIG. 7B is a circuit diagram illustrating selected portions of the master actuator and the slave of FIG. 7A, according to an exemplary embodiment.

FIG. 8 is a flowchart of a process for automatically selecting an operating mode for a HVAC actuator, according to an exemplary embodiment.

FIG. 9 is a flowchart of another process for automatically selecting an operating mode for a HVAC actuator, according to an exemplary embodiment.

FIG. 10 is a flowchart of yet another process for automatically selecting an operating mode for a HVAC actuator, according to an exemplary embodiment.

FIG. 11 is a block diagram of an actuator configured to wirelessly communicate with an external device without requiring any wired power or data connections to the actuator, according to an exemplary embodiment.

FIG. 12 is flowchart of a process for wirelessly configuring and communicating with an actuator in a HVAC system, according to an exemplary embodiment.

DETAILED DESCRIPTION

Referring generally to the FIGURES, systems and methods for configuring and communicating with HVAC devices are shown, according to various exemplary embodiments. The systems and methods described herein may be used to automatically select and set an operating mode (e.g., master, slave, normal, etc.) for actuators in a HVAC system. The systems and methods described herein may also be used to wirelessly configure, control, exchange data, or otherwise wirelessly communicate with an actuator in a HVAC system.

Actuators include any apparatus capable of providing forces and/or motion in response to a control signal. Actuators may use any of a variety of force transducers such as rotary motors, linear motors, hydraulic or pneumatic pistons/motors, piezoelectric elements, relays, comb drives, thermal bimorphs, or other similar devices to provide mechanical motion. An actuator may provide any combination of linear, curved, or rotary forces/motion. Some actuators use rotary motors to provide circular motion and/or linear motion (e.g., via a screw drive). Other actuators use linear motors to provide linear motion.

Actuators may include a variety of mechanical components such as gears, pulleys, cams, screws, levers, crankshafts, ratchets, or other components capable of changing or affecting the motion provided by the actuating/transducing element. In some embodiments, actuators do not produce significant motion in operation. For example, some actuators may be operated to exert a force or torque to an external element (e.g., a holding force) without affecting significant linear or rotary motion.

In some implementations, multiple actuators may be interconnected in a tandem arrangement. The actuators may be identical or substantially identical (e.g., the same manufacturer, model, combination of components, etc.). For example, each actuator may have an input data connection, a feedback data connection, and the same or similar internal processing components. Each actuator may be capable of operating in multiple different operating modes (e.g., as a master actuator, as a slave actuator, in a normal operating mode, etc.). The systems and methods of the present disclosure may be used to automatically identify and configure one of the actuators as a master actuator and one or more of the actuators as slave actuators based on the manner in which the actuators are interconnected.

In an exemplary arrangement, the input data connection of a first actuator may be connected (e.g., via a communications bus) to the output of a controller that provides a control signal to the first actuator. The other actuators may be arranged in tandem with the first actuator. For example, the feedback data connection of the first actuator may be connected to the input data connection of a second actuator. In some embodiments, the second actuator may be arranged in parallel with one or more additional actuators. For example, the feedback data connection of the first actuator may be connected with both the input data connection of the second actuator and the input data connections of the one or more additional actuators. In this exemplary arrangement, it would be desirable to identify the first actuator as a master actuator and the other actuators as slave actuators.

Each actuator may be configured to generate a master-slave detection signal (e.g., an analog or digital signal protocol) and to output the master-slave detection signal via its feedback data connection. In some embodiments, the master-slave detection signal is generated and output by an actuator when the actuator first receives power. If the feedback data connection of the actuator is connected with the input data connection of another actuator, the master-slave detection signal will be received at the input data connection of the other actuator.

Each actuator may be configured to monitor its input data connection for the master-slave detection signal. If an actuator detects the master-slave detection signal at its input data connection, the actuator may determine that it is arranged in a slave configuration (i.e., its input data connection is connected with the feedback data connection of another actuator) and may automatically configure itself to operate in a slave operating mode. In response to detecting the master-slave detection signal at its input data connection, the slave actuator may generate and output a reply signal. The slave actuator may output the reply signal via its input data connection.

Each actuator may be configured to monitor its feedback data connection for the reply signal. If an actuator detects the reply signal at its feedback data connection, the actuator may determine that it is arranged in a master configuration (i.e., its feedback data connection is connected with the input data connection of another actuator) and may automatically configure itself to operate in a master operating mode. The master actuator and the slave actuator may engage in bidirectional data communications via a communications bus connecting the feedback data connection of the master actuator with the input data connection of the slave actuator.

In some embodiments, if an actuator does not detect the master-slave detection signal at its input data connection and does not detect the reply signal at its feedback data connection, the actuator may determine that it is not arranged in either a master configuration or a slave configuration (i.e., it is not connected with any other actuators) and may automatically configure itself to operate in a normal operating mode.

Each actuator may have a mode indicator (e.g., a light, a speaker, an electronic display, etc.) to indicate the operating mode in which the actuator is configured. For example, if the mode indicator is a LED, the LED may be illuminated to indicate that the actuator is operating in the master operating mode. The LED may flash, blink, or illuminate a different color to indicate that the actuator is operating in the slave operating mode. The LED may turn off or illuminate yet a different color to indicate that the actuator is operating in the normal operating mode.

In some embodiments, an actuator may be configured to wirelessly communicate with an external device (e.g., a mobile device, a controller, another actuator, etc.) to send and receive various types of data related to the operation of the actuator (e.g., firmware data, control logic, model identification parameters, configuration parameters, diagnostic data, etc.). Advantageously, the actuator may communicate with the external device without requiring any wired power or data connections to the actuator. This allows the actuator to send and receive data in the event that physical access to the actuator is limited. For example, the actuator may be installed in a location that is not readily accessible by a user or service technician.

In some embodiments, the actuator can communicate with external devices while the actuator is still in its packaging at a manufacturer facility or a distributor location. The actuator can be constructed and packaged as a generic actuator and subsequently configured with suitable firmware, software, configuration parameters, or other data specific to a particular actuator model and/or implementation. Operational data such as end of line test data or other diagnostic data can be extracted from the actuator without requiring a physical data connection.

Exemplary HVAC System and Operating Environment

Referring now to FIG. 1, a perspective view of a building 10 is shown. Building 10 is serviced by a heating, ventilation, and air conditioning system (HVAC) system 20. HVAC system 20 is shown to include a chiller 22, a boiler 24, a rooftop cooling unit 26, and a plurality of air handling units (AHUs) 36. HVAC system 20 uses a fluid circulation system to provide heating and/or cooling for building 10. The circulated fluid may be cooled in chiller 22 or heated in boiler 24, depending on whether cooling or heating is required. Boiler 24 may add heat to the circulated fluid by burning a combustible material (e.g., natural gas). Chiller 22 may place the circulated fluid in a heat exchange relationship with another fluid (e.g., a refrigerant) in a heat exchanger (e.g., an evaporator). The refrigerant removes heat from the circulated fluid during an evaporation process, thereby cooling the circulated fluid.

The circulated fluid from chiller 22 or boiler 24 may be transported to AHUs 36 via piping 32. AHUs 36 may place the circulated fluid in a heat exchange relationship with an airflow passing through AHUs 36. For example, the airflow may be passed over piping in fan coil units or other air conditioning terminal units through which the circulated fluid flows. AHUs 36 may transfer heat between the airflow and the circulated fluid to provide heating or cooling for the airflow. The heated or cooled air may be delivered to building 10 via an air distribution system including air supply ducts 38 and may return to AHUs 26 via air return ducts 40. HVAC system 20 is shown to include a separate AHU 36 on each floor of building 10. In other embodiments, a single AHU (e.g., a rooftop AHU) may supply air for multiple floors or zones. The circulated fluid from AHUs 36 may return chiller 22 or boiler 24 via piping 34.

In some embodiments, the refrigerant in chiller 22 is vaporized upon absorbing heat from the circulated fluid. The vapor refrigerant may be provided to a compressor within chiller 22 where the temperature and pressure of the refrigerant are increased (e.g., using a rotating impeller, a screw compressor, a scroll compressor, a reciprocating compressor, a centrifugal compressor, etc.). The compressed refrigerant may be discharged into a condenser within chiller 22. In some embodiments, water (or another chilled fluid) flows through tubes in the condenser of chiller 22 to absorb heat from the refrigerant vapor, thereby causing the refrigerant to condense. The water flowing through tubes in the condenser may be pumped from chiller 22 to a rooftop cooling unit 26 via piping 28. Cooling unit 26 may use fan driven cooling or fan driven evaporation to remove heat from the water. The cooled water in rooftop unit 26 may be delivered back to chiller 22 via piping 30 and the cycle repeats.

Referring now to FIG. 2, a block diagram of a portion of HVAC system 20 is shown, according to an exemplary embodiment. In FIG. 2, AHU 36 is shown as an economizer type air handling unit. Economizer type air handling units vary the amount of outside air and return air used by the air handling unit for heating or cooling. For example, AHU 36 may receive return air 82 from building 10 via return air duct 40 and may deliver supply air 86 to building 10 via supply air duct 38. AHU 36 may be configured to operate exhaust air damper 60, mixing damper 62, and outside air damper 64 to control an amount of outside air 80 and return air 82 that combine to form supply air 86. Any return air 82 that does not pass through mixing damper 62 may be exhausted from AHU 36 through exhaust damper 60 as exhaust air 84.

Each of dampers 60-64 may be operated by an actuator. As shown in FIG. 2, exhaust air damper 60 may be operated by actuator 54, mixing damper 62 may be operated by actuator 56, and outside air damper 64 may be operated by actuator 58. Actuators 54-58 may communicate with an AHU controller 44 via a communications link 52. AHU controller 44 may be an economizer controller configured to use one or more control algorithms (e.g., state-based algorithms, extremum seeking control algorithms, PID control algorithms, model predictive control algorithms, etc.) to control actuators 54-58. Actuators 54-58 may receive control signals from AHU controller 44 and may provide feedback signals to AHU controller 44. Feedback signals may include, for example, an indication of a current actuator position, an amount of torque or force exerted by the actuator, diagnostic information (e.g., results of diagnostic tests performed by actuators 54-58), status information, commissioning information, configuration settings, calibration data, and/or other types of information or data that may be collected, stored, or used by actuators 54-58.

Still referring to FIG. 2, AHU 36 is shown to include a cooling coil 68, a heating coil 70, and a fan 66. In some embodiments, cooling coil 68, heating coil 70, and fan 66 are positioned within supply air duct 38. Fan 66 may be configured to force supply air 86 through cooling coil 68 and/or heating coil 70. AHU controller 44 may communicate with fan 66 via communications link 78 to control a flow rate of supply air 86. Cooling coil 68 may receive a chilled fluid from chiller 22 via piping 32 and may return the chilled fluid to chiller 22 via piping 34. Valve 92 may be positioned along piping 32 or piping 34 to control an amount of the chilled fluid provided to cooling coil 68. Heating coil 70 may receive a heated fluid from boiler 24 via piping 32 and may return the heated fluid to boiler 24 via piping 34. Valve 94 may be positioned along piping 32 or piping 34 to control an amount of the heated fluid provided to heating coil 70.

Each of valves 92-94 may be controlled by an actuator. As shown in FIG. 2, valve 92 may be controlled by actuator 88 and valve 94 may be controlled by actuator 90. Actuators 88-90 may communicate with AHU controller 44 via communications links 96-98. Actuators 88-90 may receive control signals from AHU controller 44 and may provide feedback signals to controller 44. In some embodiments, AHU controller 44 receives a measurement of the supply air temperature from a temperature sensor 72 positioned in supply air duct 38 (e.g., downstream of cooling coil 68 and heating coil 70). AHU controller 44 may operate actuators 88-90 to modulate an amount of heating or cooling provided to supply air 86 to achieve a setpoint temperature for supply air 86 or to maintain the temperature of supply air 86 within a setpoint temperature range.

In some embodiments, two or more of actuators 54-58 and/or actuators 88-90 may be arranged in a tandem configuration. For example, one actuator may be arranged as a master actuator (e.g., directly connected with AHU controller 44) and other actuators may be arranged as slave actuators (e.g., connected to a feedback data connection of the master actuator). Such a tandem arrangement is described in greater detail with reference to FIG. 3. Advantageously, each of actuators 54-58 and 88-90 may be configured to automatically determine whether it is arranged as a master actuator, a slave actuator, or not linked to any other actuators. Each of actuators 54-58 and 88-90 may be configured to automatically set its own operating mode (e.g., master, slave, non-linked, etc.) based on the determined arrangement.

Still referring to FIG. 2, HVAC system 20 is shown to include a supervisory controller 42 and a client device 46. Supervisory controller 42 may include one or more computer systems (e.g., servers, BAS controllers, etc.) that serve as enterprise level controllers, application or data servers, head nodes, master controllers, or field controllers for HVAC system 20. Supervisory controller 42 may communicate with multiple downstream building systems or subsystems (e.g., an HVAC system, a security system, etc.) via a communications link 50 according to like or disparate protocols (e.g., LON, BACnet, etc.). In some embodiments, AHU controller 44 receives information (e.g., commands, setpoints, operating boundaries, etc.) from supervisory controller 42. For example, supervisory controller 42 may provide AHU controller 44 with a high fan speed limit and a low fan speed limit. A low limit may avoid frequent component and power taxing fan start-ups while a high limit may avoid operation near the mechanical or thermal limits of the fan system. In various embodiments, AHU controller 44 and supervisory controller 42 may be separate (as shown in FIG. 2) or integrated. In an integrated implementation, AHU controller 44 may be a software module configured for execution by a processor of supervisory controller 42.

Client device 46 may include one or more human-machine interfaces or client interfaces (e.g., graphical user interfaces, reporting interfaces, text-based computer interfaces, client-facing web services, web servers that provide pages to web clients, etc.) for controlling, viewing, or otherwise interacting with HVAC system 20, its subsystems, and/or devices. Client device 46 may be a computer workstation, a client terminal, a remote or local interface, or any other type of user interface device. Client device 46 may be a stationary terminal or a mobile device. For example, client device 46 may be a desktop computer, a computer server with a user interface, a laptop computer, a tablet, a smartphone, a PDA, or any other type of mobile or non-mobile device.

Automated Master-Slave Determination and Operating Mode Selection

Referring now to FIG. 3, a block diagram illustrating a portion of HVAC system 20 is shown, according to an exemplary embodiment. HVAC system 20 is shown to include a controller 100 and several actuators 102, 104, and 106 in a tandem arrangement. Controller 100 may be an AHU controller (e.g., AHU controller 44), an economizer controller, a supervisory controller (e.g., supervisory controller 42), a zone controller, a field controller, an enterprise level controller, a motor controller, an equipment-level controller (e.g., an actuator controller) or any other type of controller that can be used in HVAC system 20.

Controller 100 is shown to include an output data connection 120 and an input data connection 122. Controller 100 may provide a control signal for actuators 102-106 via output data connection 120. In some embodiments, the control signal provided via output data connection 120 is a voltage signal. Controller 100 may modulate the voltage signal within a voltage range (e.g., 0-10 VDC) to set a rotational position for actuators 102-106. For example, a voltage of 0.0 VDC may correspond to 0 degrees of rotation and a voltage of 10.0 VDC may correspond to 90 degrees of rotation. The control signal may be communicated to actuators 102-106 via a communications bus 124 connected to output data connection 120.

Actuators 102-106 may provide controller 100 with a feedback signal indicating the current rotational position of actuators 102-106. The feedback signal may be a voltage signal similar to the control signal output by controller 100 (e.g., 0-10 VDC) and may be communicated to controller 100 via communications bus 126. Controller 100 may receive the feedback signal at input data connection 122. In some embodiments, the feedback signal includes an amount of torque or force exerted by actuators 102-106, diagnostic information (e.g., results of diagnostic tests performed by actuators 54-58), status information, commissioning information, configuration settings, calibration data, and/or other types of information or data that may be collected, stored, or used by actuators 102-106.

Actuators 102-106 may be any actuators of HVAC system 20. For example, actuators 102-106 may be damper actuators (e.g., actuators 54-58), valve actuators (e.g., actuators 88-90), fan actuators, pump actuators, or any other type of actuators that can be used in HVAC system 20. In various embodiments, actuators 102-106 may be linear proportional actuators (i.e., the rotational position of actuators 102-106 is proportional to the voltage provided by controller 100) or non-linear actuators (i.e., the rotational position of actuators 102-106 varies disproportionately with the voltage provided by controller 100).

In some embodiments, actuators 102-106 are identical or substantially identical (e.g., the same manufacturer, the same model, the same internal components, etc.). For example, each of actuators 102-106 is shown to include an input data connection (i.e., input data connections 108, 110, and 112) and a feedback data connection (i.e., feedback data connections 114, 116, and 118). Actuators 102-106 may have the same or similar internal processing components (e.g., a processing circuit having a processor, memory, and memory modules). Each of actuators 102-106 may be capable of operating in multiple different operating modes. For example, each of actuators 102-106 may be capable of operating as a master actuator, as a slave actuator, or in a normal (e.g., non-linked) operating mode. Advantageously, each of actuators 102-106 may be configured to automatically identify itself as a master actuator, a slave actuator, or a non-linked actuator and may set its own operating mode based on the manner in which it is interconnected with the other actuators.

Still referring to FIG. 3, actuators 102-106 are shown in a tandem arrangement, according to an exemplary embodiment. In the exemplary tandem arrangement, input data connection 108 of actuator 102 is connected (e.g., via communications bus 124) to output data connection 120 of controller 100. Feedback data connection 114 of actuator 102 may be connected to input data connection 110 of actuator 104 via communications bus 128. Communications bus 128 may be a wired or wireless communications link and may use any of a variety of disparate communications protocols (e.g., BACnet, LON, WiFi, Bluetooth, NFC, TCP/IP, etc.). Actuator 104 may be arranged in parallel with actuator 106. For example, feedback data connection 114 of actuator 102 may be connected with both input data connection 110 of actuator 104 and input data connection 112 of actuator 106 via communications bus 128.

As shown in FIG. 3, actuator 102 is arranged as a master actuator and actuators 104-106 are arranged as slave actuators. A master actuator may be defined as an actuator having an input data connection that is connected to the output data connection of a controller. The feedback data connection of a master actuator may be connected with the input data connections of one or more slave actuators. A slave actuator may be defined as an actuator having an input data connection that is connected to the feedback data connection of a master actuator. The feedback data connection of a slave actuator may be connected to the input data connection of the controller or may not be connected with anything.

Referring now to FIG. 4, a block diagram illustrating actuators 102 and 104 in greater detail is shown, according to an exemplary embodiment. FIG. 4 illustrates another tandem configuration in which actuator 102 is arranged as a master actuator and actuator 104 is arranged as a slave actuator. In FIG. 4, output data connection 120 of controller 100 is connected with input data connection 108 of actuator 102 via communications bus 124. Feedback data connection 114 of actuator 102 may be connected with input data connection 110 of actuator 104 via a bidirectional communications link 228. Bidirectional communications link 228 may be implemented as a communications bus (e.g., communications bus 128), a wired communications interface, or a wireless communications interface. Bidirectional communications link 228 and may utilize any of a variety of disparate communications protocols (e.g., BACnet, LON, TCP/IP, Bluetooth, NFC, WiFi, etc.). Feedback data connection 116 of actuator 104 may be connected with input data connection 122 of controller 100 via communications bus 126.

Actuators 102 and 104 may be identical or substantially identical and may include the same or similar internal processing components. For example, each of actuators 102-104 is shown to include a processing circuit 134 including a processor 136 and memory 138. Processor 136 may be a general purpose or specific purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable processing components. Processor 136 is configured to execute computer code or instructions stored in memory 138 or received from other computer readable media (e.g., CDROM, network storage, a remote server, etc.).

The term “corresponding actuator” is used throughout this description to specify a particular actuator with respect to a given component. The corresponding actuator for any given component is the actuator that includes the component. For example, the corresponding actuator for all of the components of actuator 102 is actuator 102, whereas the corresponding actuator for all of the components of actuator 104 is actuator 104. The same reference numbers are used for many of the components of each actuator to indicate that each actuator may be identical or substantially identical. Advantageously, each processing circuit 134 may be configured to automatically determine whether the corresponding actuator is arranged as a master actuator, a slave actuator, or in a non-linked arrangement notwithstanding the identical or substantially identical components of each actuator. Processing circuit 134 may select an operating mode for the corresponding actuator based on a result of the determination.

Memory 138 may include one or more devices (e.g., memory units, memory devices, storage devices, etc.) for storing data and/or computer code for completing and/or facilitating the various processes described in the present disclosure. Memory 138 may include random access memory (RAM), read-only memory (ROM), hard drive storage, temporary storage, non-volatile memory, flash memory, optical memory, or any other suitable memory for storing software objects and/or computer instructions. Memory 138 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. Memory 138 may be communicably connected to processor 136 via processing circuit 134 and may include computer code for executing (e.g., by processor 136) one or more processes described herein.

Still referring to FIG. 4, memory 138 is shown to include a feedback generator 140. Each feedback generator 140 may be configured to generate a master-slave detection signal (e.g., a series of digital pulses, an analog signal, etc.) and to output the master-slave detection signal via the feedback data connection of the corresponding actuator (e.g., feedback data connection 114 or 116). In some embodiments, feedback generator 140 generates and outputs the master-slave detection signal when the corresponding actuator first receives power. In some embodiments, feedback generator 140 generates and outputs the master-slave detection signal when the corresponding actuator enters a calibration mode. An actuator may enter the calibration mode, for example, in response to a signal from another component of HVAC system 20 (e.g., a controller, a client device, another actuator, etc.) and/or in response to a user-operable switch of the actuator being moved into a calibration position.

The master-slave detection signal output at feedback data connection 114 of actuator 102 may be received at input data connection 110 of actuator 104 since feedback data connection 114 is connected with input data connection 110 via bidirectional communications link 228. However, the master-slave detection signal output at feedback data connection 116 may not be received at input data connection 108 since no direct connection exists between feedback data connection 116 and input data connection 108. This distinction may be used to identify actuator 102 as a master actuator and to identify actuator 104 as a slave actuator, as described in greater detail below.

Still referring to FIG. 4, memory 138 is shown to include a master signal detector 142. Master signal detector 142 may be configured to monitor the input data connection of the corresponding actuator for the master-slave detection signal. In the arrangement shown in FIG. 4, the master signal detector 142 of actuator 104 may detect the master-slave detection signal because input data connection 110 is connected with the feedback data connection of another actuator (i.e., feedback data connection 114). However, the master signal detector 142 of actuator 102 may not detect the master-slave detection signal because input data connection 108 is not directly connected with the feedback data connection of any other actuator. In response to detecting the master-slave detection signal, master signal detector 142 may generate a notification for operating mode selector 144 and/or reply signal generator 146. The notification may be an analog or digital signal indicating that the master-slave detection signal has been detected at the input data connection of the corresponding actuator.

Operating mode selector 144 may be configured to select an operating mode for the corresponding actuator. If operating mode selector 144 receives an input indicating that the master-slave detection signal has been detected at the input data connection of the corresponding actuator, operating mode selector 144 may determine that the actuator is arranged in a slave configuration and may select a slave operating mode for the actuator.

Reply signal generator 146 may be configured to generate and output a reply signal. The reply signal may be a series of digital pulses, an analog signal, or any other type of data signal. In some embodiments, reply signal generator 146 generates and outputs the reply signal in response to a determination (e.g., by operating mode selector 144) that the actuator is arranged in a slave configuration and/or in response to a selection of the slave operating mode. In some embodiments, reply signal generator 146 generates and outputs the reply signal in response to receiving an input (e.g., from master signal detector 142) indicating that the master-slave detection signal has been detected at the input data connection of the corresponding actuator.

In the arrangement shown in FIG. 4, the reply signal generator 146 of actuator 104 may generate and output a reply signal because the master-slave detection signal is received and detected at input data connection 110. However, the reply signal generator 146 of actuator 102 may not generate or output a reply signal because the master-slave detection signal is not received or detected at input data connection 108.

Reply signal generator 146 may output the reply signal via the input data connection of the corresponding actuator. The reply signal may be communicated from the input data connection back to the feedback data connection of the actuator from which the master-slave detection signal was received. For example, the reply signal generated by the reply signal generator 146 of actuator 104 may be output via data connection 110 and communicated back to feedback data connection 114 via bidirectional communications link 228. Actuators 102-104 may engage in bidirectional data communications via bidirectional communications link 228. For example, actuator 102 may send the master-slave detection signal via bidirectional communications link 228 and may receive the reply signal from actuator 104 via bidirectional communications link 228.

Still referring to FIG. 4, memory 138 is shown to include a reply signal detector 148. Reply signal detector 148 may be configured to monitor the feedback data connection of the corresponding actuator for the reply signal. In the arrangement shown in FIG. 4, the reply signal detector 148 of actuator 102 may detect the reply signal that is generated by the reply signal generator in actuator 104 and communicated back to feedback data connection 114 of actuator 102. However, the reply signal detector 148 of actuator 104 may not detect the reply signal because feedback data connection 116 does not receive the reply signal.

In response to detecting the reply signal, reply signal detector 148 may generate a notification for operating mode selector 144. The notification may be an analog or digital signal indicating that the reply signal has been received at the feedback data connection of the corresponding actuator. If operating mode selector 144 receives an input indicating that the reply signal has been received at the feedback data connection of the corresponding actuator, operating mode selector 144 may determine that the actuator is arranged in a master configuration and may select a master operating mode for the actuator.

In some embodiments, if an actuator does not detect the master-slave detection signal at its input data connection and does not detect the reply signal at its feedback data connection, operating mode selector 144 may determine that the actuator is arranged in neither the master configuration nor the slave configuration. For example, the actuator may not be connected with any other actuators. In response to a determination that the actuator is arranged in neither the master configuration nor the slave configuration, operating mode selector 144 may select a normal (e.g., non-linked) operating mode.

Actuators 102-104 may behave differently based on whether operating mode selector 144 selects the master operating mode, the slave operating mode, or the normal operating mode. For example, in the master operating mode, an actuator may accept an input signal of any value within an input signal range (e.g., 0-10 VDC) and may produce a feedback signal at one or more discrete values (e.g., 0 VDC, 5 VDC, 10 VDC, etc.). In the slave operating mode, an actuator may accept an input signal at one or more discrete values (e.g., 0 VDC, 5 VDC, 10 VDC, etc.) and may produce a feedback signal of any value within a feedback signal range (e.g., 0-10 VDC). In the normal operating mode, an actuator may accept an input signal of any value within an input signal range (e.g., 0-10 VDC) and may produce a feedback signal of any value within a feedback signal range (e.g., 0-10 VDC).

Still referring to FIG. 4, memory 138 is shown to include a proportional input module 154. Proportional input module 154 may be configured to translate a control signal received from controller 100 into an amount of rotation, linear motion, force, torque, or other physical output provided by transducer 156. For example, proportional input module 154 may translate an input voltage of 0.0 VDC to 0 degrees of rotation and may translate an input voltage of 10.0 VDC to 90 degrees of rotation. The output rotation may be provided to transducer 156 directly from proportional input module 154 or indirectly (e.g., via feedback generator 140). Feedback generator 140 may include one or more filters (e.g., low pass filters), gain stages, and/or buffers applied to the output rotation before the output rotation is communicated as a feedback signal to controller 100. Controller 100 may use the feedback signal to determine the current rotational position of a motor, valve, or damper controlled by the actuator.

In some embodiments, actuators 102-106 include a mode indicator 150. Mode indicator 150 may be a light, a speaker, an electronic display, or other component configured to indicate the operating mode selected by operating mode selector 144. For example, mode indicator 150 may be a LED and may be illuminated to indicate that the actuator is operating in the master operating mode. The LED may flash, blink, or illuminate a different color to indicate that the actuator is operating in the slave operating mode. The LED may turn off or illuminate yet a different color to indicate that the actuator is operating in the normal operating mode.

Referring now to FIGS. 5-6, a pair of block diagrams illustrating two processes 500 and 600 are shown, according to an exemplary embodiment. Processes 500 and 600 may be performed by one or more actuators of a HVAC system to automatically identify an arrangement of the actuators and to automatically select an select an operating mode. In both processes 500 and 600, a bidirectional communications link 228 is formed between a master actuator 102 and a slave actuator 104. Bidirectional communications link 228 connects the feedback data connection 114 of master actuator 102 with the input data connection 110 of slave actuator 104. Bidirectional communications link 228 may be used to exchange various types of data between actuators 102 and 104. For example, bidirectional communications link 228 may be used to communicate a master-slave detection signal, a reply signal, diagnostic information, status information, configuration settings, calibration data, or other types of information or data that may be collected, stored, or used by actuators 102-104.

Referring specifically to FIG. 5, process 500 is shown to include master actuator 102 sending a detection signal to slave actuator 104 via bidirectional communications link 228 (step 502). Actuators 102 and 104 may be identical or substantially identical and may be distinguished only by the manner in which actuators 102-104 are interconnected. Either actuator may be capable of functioning as a master actuator or a slave actuator. At the time the detection signal is communicated, it may be unknown whether each of actuators 102-104 is arranged as a master actuator or a slave actuator.

Master actuator 102 may generate the detection signal according to stored criteria and may output the detection signal via feedback data connection 114. The detection signal may be a series of digital pulses, an analog signal, or any other type of data signal. Slave actuator 104 may monitor input data connection 110 for the detection signal. Slave actuator 104 may identify the detection signal by comparing the signals received at input data connection 110 with a stored representation of the detection signal.

In response to receiving the detection signal at input data connection 110, slave actuator 104 may set its operating mode to a slave operating mode (step 504) and may send a reply signal back to master actuator 102 via bidirectional communications link 228 (step 506). Slave actuator 104 may generate the reply signal according to stored criteria and may output the reply signal via input data connection 110. The reply signal may be a series of digital pulses, an analog signal, or any other type of data signal.

Master actuator 102 may monitor feedback data connection 114 for the reply signal. Master actuator 102 may identify the reply signal by comparing the signals received at feedback data connection 114 with a stored representation of the reply signal. In response to receiving the reply signal at feedback data connection 114, master actuator 102 may set its operating mode to a master operating mode (step 508).

In process 500, master actuator 102 initiates the master-slave identification process by sending the detection signal to slave actuator 104. Slave actuator 104 then responds with the reply signal. In other embodiments, slave actuator 104 may initiate the process and master actuator 102 may respond with the reply signal. Such an alternative process is illustrated in FIG. 6.

Referring specifically to FIG. 6, process 600 is shown to include slave actuator 104 sending a detection signal to master actuator 102 via bidirectional communications link 228 (step 602). Slave actuator 104 may generate the detection signal according to stored criteria and may output the detection signal via input data connection 110. Master actuator 102 may monitor feedback data connection 114 for the detection signal. Master actuator 102 may identify the detection signal by comparing the signals received at feedback data connection 114 with a stored representation of the detection signal.

In response to receiving the detection signal at feedback data connection 114, master actuator 102 may set its operating mode to a master operating mode (step 604) and may send a reply signal back to slave actuator 104 via bidirectional communications link 228 (step 606). Master actuator 102 may generate the reply signal according to stored criteria and may output the reply signal via feedback data connection 114.

Slave actuator 104 may monitor input data connection 110 for the reply signal. Slave actuator 104 may identify the reply signal by comparing the signals received at input data connection 110 with a stored representation of the reply signal. In response to receiving the reply signal at input data connection 110, slave actuator 104 may set its operating mode to a slave operating mode (step 608).

Referring now to FIG. 7A, a block diagram illustrating master actuator 102 and slave actuator 104 in greater detail is shown, according to an exemplary embodiment. Actuators 102 and 104 may be identical or substantially identical and may include the same or similar components. For example, each of actuators 102 and 104 is shown to include an input connection 736, a feedback connection 734, a slave handshake circuit 702, a proportional input and master detection circuit 710, a microcontroller 716, a slave detection circuit 718, and a feedback output circuit 724.

The input connection 736 of master actuator 102 may be connected with output data connection 120 of controller 100. Feedback connection 734 of master actuator 102 may be connected via a bidirectional communications link 732 with input connection 736 of slave actuator 104. Feedback connection 734 of slave actuator 104 may be connected with input connection 122 of controller 100.

Proportional input and master detection circuit 710 may be configured to perform the functions of proportional input module 154 and master signal detector 142, as described with reference to FIG. 4. For example, proportional input and master detection circuit 710 is shown to include a division module 712, a low pass filter 714, and a voltage comparator 708. Division module 712 may apply a division factor to the input signal received at input connection 736. Division module 712 may provide the divided signal to low pass filter 714. Low pass filter 714 may filter the divided signal from division module 712 and may provide the filtered signal as an analog input 742 to voltage comparator 708 and microcontroller 716. Voltage comparator 708 may be configured to monitor the output of low pass filter 714 for the master detection signal. The master detection signal may be received from a master actuator if input connection 736 is connected with the feedback connection of another actuator. Voltage comparator 708 may provide an analog or digital input 740 to microcontroller 716 indicating whether the master detection signal is received at input connection 736.

Microcontroller 716 may be configured to generate the master detection signal and to provide the master detection signal as an output via feedback connection 734. In some embodiments, microcontroller 716 generates the master detection signal according to a signal protocol. In some embodiments, the master detection signal is a series of voltage pulses. Microcontroller 716 may output the master detection signal via PWM/DO output 744. PWM/DO output 744 may communicate the master detection signal to feedback connection 734 via feedback output circuit 724.

Feedback output circuit 724 is shown to include a low pass filter 726, a gain stage 728, and a buffer stage 730. Low pass filter 726 may filter the output signal from PWM/DO output 744 of microcontroller 716. Gain stage 728 may multiply the filtered signal from low pass filter 726 by a multiplication factor and provide the multiplied signal to buffer stage 730. Buffer stage 730 may output the signal from gain stage 728 as a feedback signal via feedback connection 734.

Still referring to FIG. 7A, microcontroller 716 may be configured to receive an analog or digital input 740 indicating whether the master detection signal has been received at input connection 736. If input 740 indicates that the master detection signal has been received, microcontroller 716 may generate a reply signal and provide the reply signal as an analog or digital output 746 to input connection 736. In other embodiments, microcontroller 716 causes slave handshake circuit 702 to generate the reply signal. For example, microcontroller 716 may provide a command to slave acknowledge circuit 704 via output 746 and slave acknowledge circuit 704 may generate the reply signal in response to receiving the command from microcontroller 716. If input 740 indicates that the master detection signal has been received, microcontroller 716 may instruct slave acknowledge circuit 704 to generate the reply signal. The reply signal may be communicated through bidirectional communications link 732 to the other controller (i.e., back to the master controller).

Microcontroller 716 may be configured to set an operating mode for the corresponding actuator. For example, if digital input 740 indicates that the master detection signal has been received, microcontroller 716 may set the corresponding actuator to operate in the slave operating mode. Microcontroller 716 may be configured to receive analog input 748 and to determine whether analog input 748 matches the reply signal. If analog input 748 matches the reply signal, microcontroller 716 may set the corresponding actuator to operate in the master operating mode. If microcontroller 716 does not observe either the master detection signal or the reply signal as an input, microcontroller 716 may set the corresponding actuator to operate in a normal (i.e., non-linked) operating mode.

Slave detection circuit 718 may be configured to perform the functions of reply signal detector 148, as described with reference to FIG. 4. For example, slave detection circuit 718 may monitor feedback connection 734 for the reply signal received via the bidirectional communications link 732. Slave detection circuit 718 is shown to include a voltage comparator 722 and a low pass filter 720. Voltage comparator 722 may determine whether the signal received via bidirectional communications link 732 matches the reply signal and may provide a reply detection signal to low pass filter 720 when the reply signal is detected. Low pass filter 720 may filter the reply detection signal from voltage comparator 722 and may provide the filtered signal as an analog input 748 to microcontroller 716.

Referring now to FIG. 7B, a circuit diagram illustrating selected portions of master actuator 102 and slave actuator 104 in greater detail is shown, according to an exemplary embodiment. Master actuator 102 is shown to include a feedback output circuit 724. Feedback output circuit 724 may include a voltage source V₁ configured to generate a voltage signal V_(signal) at wire 752. V_(signal) may be a series of digital pulses within a predetermined voltage range (e.g., 0-10 VDC). In some embodiments, V_(signal) is a pulse width modulated signal. Feedback output circuit 724 may transform V_(signal) into a feedback voltage signal V_(fb) and output the feedback voltage signal V_(fb) at feedback connection 734.

Feedback connection 734 of master actuator 102 may be connected via bidirectional communications link 732 with input connection 736 of slave actuator 104. Slave actuator 104 may receive the feedback voltage signal V_(fb) at input connection 736. Slave actuator 104 may pass the feedback voltage signal V_(fb) through a series of resistors (e.g., R7, R4, R1, and R2) and an amplifier

Slave actuator 104 is shown to include a master detection circuit 710. Master detection circuit 710 may compare the voltage signal V_(fb) (or a voltage signal based on V_(fb)) with a reference voltage V_(ref). In some embodiments, V_(ref) is a constant voltage signal. Master detection circuit 710 may output a master detection signal V_(master) _(_) _(detect), which may be communicated to microcontroller 716 of slave actuator 104. The master detection signal V_(master) _(_) _(detect) may be a series of digital pulses.

Microcontroller 716 may analyze the master detection signal V_(master) _(_) _(detect) to determine whether master detection signal V_(master) _(_) _(detect) matches a stored master detection signal. In response to a determination that the master detection signal V_(master) _(_) _(detect) matches the stored master detection signal, microcontroller 716 may set the operating mode of slave actuator 104 to a slave operating mode.

Slave actuator 104 is shown to include a reply signal circuit 750. Reply signal circuit 750 may receive a reply signal V_(slv) _(_) _(ack) from microcontroller 716 in response to microcontroller 716 determining that the master detection signal received at master detection circuit 710 matches the stored master detection signal. Reply signal circuit 750 may transmit the reply signal V_(slv) _(_) _(ack) to input connection 736. The reply signal V_(slv) _(_) _(ack) may be communicated to master actuator 102 across bidirectional communications link 732. Master actuator 102 may receive the reply signal V_(slv) _(_) _(ack) at feedback connection 734.

Master actuator 102 is shown to include a slave detection circuit 718. Slave detection circuit may receive the reply signal V_(slv) _(_) _(ack) from feedback connection 734. Slave detection circuit may generate a slave detection signal V_(slv) _(_) _(detect), which may be communicated to microcontroller 716 of master actuator 102.

Microcontroller 716 may analyze the slave detection signal V_(slv) _(_) _(detect) to determine whether the slave detection signal matches a stored slave detection signal. In response to a determination that the slave detection signal V_(slv) _(_) _(detect) matches the stored slave detection signal, microcontroller 716 may set the operating mode of master actuator 102 to a master operating mode.

Referring now to FIG. 8, a flowchart of a process 800 for automatically selecting an operating mode for a HVAC actuator is shown, according to an exemplary embodiment. Process 800 may be performed by any actuator in a HVAC system (e.g., damper actuators 54-58, valve actuators 88-90, fan actuators, pump actuators, etc.). In some embodiments, process 800 is performed by a processing circuit of a HVAC actuator. For example, process 800 may be performed by processing circuit 134 or by microcontroller 716 of one or more of actuators 102-106, as described with reference to FIGS. 4-7.

Process 800 is shown to include transmitting a first data signal via a bidirectional communications link between a first actuator and a second actuator (step 802). The first data signal may be a master-slave detection signal or a reply signal. If the first data signal is a master-slave detection signal, the first data signal may be transmitted upon the actuator receiving power. If the first data signal is a reply signal, the first data signal may be transmitted in response to receiving the master-slave detection signal from another actuator via a bidirectional communications link.

Process 800 is shown to include monitoring the bidirectional communications link for a second data signal (step 804). The second data signal may be a reply signal or a master-slave detection signal. If the first data signal is a master-slave detection signal, the second data signal may be the reply signal. If the first data signal is a reply signal, the second data signal may be the master-slave detection signal.

In various embodiments, the order of steps 802 and steps 804 may be reversed. For example, if the first data signal is the master-slave detection signal and the second data signal is the reply signal, step 802 may be performed before step 804. However, if the first data signal is the reply signal and the second data signal is the master-slave detection signal, step 802 may be performed before after 804.

Process 800 is shown to include selecting an operating mode for at least one of the first actuator and the second actuator based on whether the second data signal is received via the bidirectional communications link (step 806). If the second data signal is the master-slave detection signal, step 806 may include selecting the slave operating mode for the actuator. If the second data signal is the reply signal, step 806 may include selecting the master operating mode for the actuator. If neither the master-slave detection signal nor the reply signal are received via the bi-directional communications link, step 806 may include selecting the non-linked (e.g., normal) operating mode for the actuator.

Referring now to FIG. 9, a flowchart of a process 900 for automatically selecting an operating mode for a HVAC actuator is shown, according to an exemplary embodiment. Process 900 may be performed by any actuator in a HVAC system (e.g., damper actuators 54-58, valve actuators 88-90, fan actuators, pump actuators, etc.). In some embodiments, process 900 is performed by a processing circuit of a HVAC actuator. For example, process 900 may be performed by processing circuit 134 or by microcontroller 716 of one of actuators 102-106, as described with reference to FIGS. 3-7.

Process 900 is shown to include transmitting a master-slave detection signal via a feedback data connection of an actuator (step 902). If the actuator is arranged as a master actuator, the feedback data connection may be connected with an input data connection of another actuator. The connection between actuators may be a bidirectional communications link. However, if the actuator is arranged as a slave actuator or in a non-linked arrangement, the feedback data connection may not be connected with the input data connection of another actuator.

Process 900 is shown to include monitoring an input data connection of the actuator for the master-slave detection signal (step 904). If the actuator is arranged as a slave actuator, the input data connection may be connected with a feedback data connection of another actuator. If the other actuator also transmits the master-slave detection signal via its feedback data connection, the master-slave detection signal will be received at the input data connection in step 904. However, if the actuator is arranged as a master actuator or in a non-linked arrangement, the input data connection may not be connected with the feedback connection of another actuator and the master-slave detection signal will not be received in step 904.

Process 900 is shown to include transmitting a reply signal via the input data connection in response to detecting the master-slave detection signal at the input data connection (step 906). Step 906 is an optional step that may be performed if the master-slave detection signal is detected in step 904. The master-slave detection signal may be detected in step 904 if the actuator is arranged as a slave actuator. If the actuator is not arranged as a slave actuator, the master-slave detection signal may not be received in step 904 and step 906 may not be performed.

Process 900 is shown to include monitoring the feedback data connection for the reply signal (step 908). If the actuator is arranged as a master actuator, the feedback data connection may be connected with an input data connection of another actuator. If the other actuator also performs process 900, the reply signal may be received in step 908. However, if the actuator is arranged as a slave actuator or in a non-linked arrangement, the feedback data connection may not be connected with the input data connection of another actuator and the reply signal will not be received in step 908.

Process 900 is shown to include selecting an operating mode for the actuator based on whether the master-slave detection signal or the reply signal is detected by the monitoring (step 910). If the monitoring in step 904 detects the master-slave detection signal, step 910 may include setting the operating mode for the actuator to a slave operating mode. If the monitoring in step 908 detects the reply signal, step 910 may include setting the operating mode for the actuator to a master operating mode. If neither of the monitoring steps detect the master-slave detection signal or the reply signal, step 910 may include setting the operating mode for the actuator to a non-linked (e.g., normal) operating mode.

Referring now to FIG. 10, a flowchart of a process 1000 for automatically selecting an operating mode for a HVAC actuator is shown, according to an exemplary embodiment. Process 1000 may be performed by any actuator in a HVAC system (e.g., damper actuators 54-58, valve actuators 88-90, fan actuators, pump actuators, etc.). In some embodiments, process 1000 is performed by a processing circuit of a HVAC actuator. For example, process 1000 may be performed by processing circuit 134 or by microcontroller 716 of one of actuators 102-106, as described with reference to FIGS. 3-7.

Process 1000 is shown to include transmitting a master signal via a feedback data connection of an actuator (step 1002). If the actuator is arranged as a master actuator, the feedback data connection may be connected with an input data connection of another actuator. The connection between actuators may be a bidirectional communications link. However, if the actuator is arranged as a slave actuator or in a non-linked arrangement, the feedback data connection may not be connected with the input data connection of another actuator.

Process 1000 is shown to include monitoring an input data connection of the actuator for the master signal (step 1004). If the actuator is arranged as a slave actuator, the input data connection may be connected with a feedback data connection of another actuator. If the other actuator also transmits the master signal via its feedback data connection, the master signal will be received at the input data connection in step 1004. However, if the actuator is arranged as a master actuator or in a non-linked arrangement, the input data connection may not be connected with the feedback connection of another actuator and the master signal will not be received in step 1004.

Process 1000 is shown to include determining whether the master signal is detected at the input data connection (step 1006). If the master signal is detected at the input data connection of the actuator in step 1004 (i.e., the result of step 1006 is “yes”), process 1000 may proceed to transmitting a reply signal via the input data connection (step 1008) and selecting a slave operating mode for the actuator (step 1010).

If the master signal is not detected at the input data connection of the actuator in step 1004 (i.e., the result of step 1006 is “no”), process 1000 may proceed to monitoring the feedback data connection for the reply signal (step 1012). If the actuator is arranged as a master actuator, the feedback data connection may be connected with an input data connection of another actuator. If the other actuator also performs process 1000, the reply signal may be received in step 1012. However, if the actuator is arranged as a slave actuator or in a non-linked arrangement, the feedback data connection may not be connected with the input data connection of another actuator and the reply signal will not be received in step 1012.

Process 1000 is shown to include determining whether the reply signal is detected at the feedback data connection (step 1014). If the reply signal is detected at the feedback data connection of the actuator in step 1012 (i.e., the result of step 1014 is “yes”), process 1000 may proceed to selecting a master operating mode for the actuator (step 1016). If the reply signal is not detected at the feedback data connection of the actuator in step 1012 (i.e., the result of step 1014 is “no”), process 1000 may proceed to selecting a non-linked operating mode for the actuator (step 1018).

Wireless Configuration and Communication

Referring now to FIG. 11, a block diagram of an actuator 1100 is shown, according to an exemplary embodiment. Actuator 1100 may be configured to wirelessly communicate with an external device (e.g., mobile device 1140, a controller, another actuator, etc.) to send and receive various types of data related to the operation of actuator 1100 (e.g., firmware data, control logic, model identification parameters, configuration parameters, diagnostic data, etc.). Advantageously, actuator 1100 may communicate with the external device without requiring any wired power or data connections to actuator 1100. This allows actuator 1100 to send and receive data in the event that physical access to actuator 1100 is limited. For example, actuator 1100 may be installed in a location that is not readily accessible by a user or service technician.

In some embodiments, actuator 1100 can communicate with external devices while actuator 1100 is still in its packaging at a manufacturer facility or a distributor location. Actuator 1100 can be constructed and packaged as a generic actuator and subsequently configured with suitable firmware, software, configuration parameters, or other data specific to a particular actuator model and/or implementation. Operational data such as end of line test data or other diagnostic data can be extracted from actuator 1100 without requiring a physical data connection.

Still referring to FIG. 11, actuator 1100 is shown to include a transducer 1102, a processing circuit 1104, a power circuit 1110, and a wireless transceiver 1112. Transducer 1102 may be any apparatus capable of providing forces and/or motion in response to a control signal. For example, transducer 1102 may be any of a variety of mechanical transducers such as rotary motors, linear motors, hydraulic or pneumatic pistons/motors, piezoelectric elements, relays, comb drives, thermal bimorphs, or other similar devices to provide mechanical motion. Transducer 1102 may provide any combination of linear, curved, or rotary forces/motion.

In some embodiments, transducer 1102 is connected with one or more mechanical components (e.g., gears, pulleys, cams, screws, levers, crankshafts, ratchets, etc.) capable of changing or affecting the motion provided by transducer 1102. In some embodiments, transducer 1102 may not produce significant motion in operation. For example, transducer 1102 may be operated to exert a force or torque to an external element (e.g., a holding force) without affecting significant linear or rotary motion.

Processing circuit 1104 may be configured to operate transducer 1102. Processing circuit 1104 is shown to include a processor 1106 and memory 1108. Processor 1106 may be a general purpose or specific purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable processing components. Processor 1106 may be configured to execute computer code or instructions stored in memory 1108 or received from other computer readable media (e.g., CDROM, network storage, a remote server, etc.).

Memory 1108 may include one or more devices (e.g., memory units, memory devices, storage devices, etc.) for storing data and/or computer code for completing and/or facilitating the various processes described in the present disclosure. Memory 1108 may include random access memory (RAM), read-only memory (ROM), hard drive storage, temporary storage, non-volatile memory, flash memory, optical memory, or any other suitable memory for storing software objects and/or computer instructions. Memory 1108 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. Memory 1108 may be communicably connected to processor 1106 via processing circuit 1104 and may include computer code for executing (e.g., by processor 1106) one or more processes described herein.

Memory 1108 may store various types of data related to the operation of actuator 1100. For example, memory 1108 is shown to include firmware 1120, control logic 1122, and configuration parameters 1128. In some embodiments, control logic 1122 is a component of firmware 1120. Control logic 1122 may include one or more control programs that are used by processing circuit 1104 to operate transducer 1102. The control program may include logic for operating transducer 1102 based on variable configuration parameters (e.g., configuration parameters 1128) that are separate from the control program. Configuration parameters 1128 may include, for example, operational parameters such as actuation span (e.g., linear distance, degrees of rotation, etc.), offset, actuation speed, timing, or other parameters that configure actuator 1100 for a specific implementation.

Memory 1108 is shown to include model identification parameters 1126. In some embodiments, processing circuit 1104 is capable of operating multiple different actuator models. Model identification parameters 1126 may identify a particular actuator model and/or define configuration settings for a specific actuator model. Processing circuit 1104 may use model identification parameters 1126 to operate transducer 1102 according to configuration settings and/or control logic specific to the actuator model identified by model identification parameters 1126.

Memory 1108 is shown to include hyperlinks 1124. Hyperlinks 1124 may be links to a product information webpage, a product catalog, a product manual, an installation manual, an order form, or any other resource related to actuator 1100. In some embodiments, hyperlinks 1124 are specific to a particular actuator model defined by model identification parameters 1126. Hyperlinks 1124 may be communicated to a client device (e.g., mobile device 1140) via wireless transceiver 1112 and used by the client device to locate various resources associated with actuator 1100.

Memory 1108 is shown to include a diagnostics module 1132, diagnostics results 1134, and log data 1136. Diagnostics module 1132 may be configured to perform a diagnostic test of actuator 1100. Diagnostic tests may include, for example, a span or range test, a force/torque test, a calibration test, a failure modes test, a timing/speed test, or any other type of diagnostic test that can be performed by actuator 1100. Results of the diagnostic tests may be stored in memory 1108 as diagnostics results 1134. Diagnostics results 1134 may be communicated to an external system or device (e.g., a system controller, a field controller, an economizer controller, a client device, a factory or laboratory diagnostics system, etc.) via wireless transceiver 1112.

Log data 1136 may include any information related to the operation of actuator 1100. For example, log data 1136 may include actuator positions, control signal values, feedback signal values, an amount of force or torque exerted by actuator 1100, a measured temperature, or any other variable generated or used by actuator 1100. Log data 1136 may store information with time stamps indicating a time at which the stored values were used or observed by actuator 1100. Log data 1136 may be communicated to an external system or device to evaluate actuator performance and/or to perform external diagnostics.

Memory 1108 is shown to include a master/slave detection module 1130. Master-slave detection module 1130 may include the functionality of feedback generator 140, master signal detector 142, reply signal generator 146, reply signal detector 148, and operating mode selector 144, as described with reference to FIG. 4. For example, master-slave detection module 1130 may be configured to use a master-slave detection signal communicated via wireless transceiver 1112 and/or wired communications interface 1114 to select an operating mode for actuator 1100. The operating modes may include a master operating mode, a slave operating mode, and a non-linked operating mode. Processing circuit 1104 may be configured to operate transducer 1102 in response to a control signal received wireless transceiver 1112 and/or wired communications interface 1114 according to the selected operating mode.

Still referring to FIG. 11, actuator 1100 is shown to include a power circuit 1110. Power circuit 1110 may be configured to draw power from a wireless signal (e.g., an alternating magnetic or electric field) received via wireless transceiver 1112. For example, wireless transceiver 1112 may include an antenna coil that is exposed to a magnetic or electric field. The field may be produced by mobile device 1140 or another external device. In some embodiments, the magnetic or electric field is a NFC field (i.e., an alternating magnetic field with a frequency of approximately 13.56 MHz, compatible with near field communications (NFC) devices). The magnetic field may induce a voltage in power circuit 1110. In some embodiments, power circuit 1110 stores energy derived from the wireless signal using one or more capacitors.

Advantageously, power circuit 1110 may be configured to power processing circuit 1104 and wireless transceiver 1112 using the power drawn from the wireless signal received at wireless transceiver 1112. This advantage allows actuator 1100 to engage in bidirectional communications with an external device regardless of whether actuator 1100 receives power from a wired power connection. For example, actuator 1100 can communicate with external devices while actuator 1100 is still in its packaging at a manufacturer facility or a distributor location. Actuator 1100 can be constructed and packaged as a generic actuator and subsequently configured with suitable firmware, software, configuration parameters, or other data specific to a particular actuator model and/or implementation.

Still referring to FIG. 11, actuator 1100 is shown to include a wireless transceiver 1112. Wireless transceiver 1112 may be configured to facilitate bidirectional wireless data communications between processing circuit 1104 and an external device (e.g., mobile device 1140). Wireless transceiver may be used by processing circuit 1104 to transmit data stored in memory 1108 to the external device and/or to wirelessly receive data from the external device. In some embodiments, the external device includes a user interface 1142 that may be used to view the data communicated via wireless transceiver 1112.

Data communicated via wireless transceiver 1112 may include firmware data 1120, control logic data 1122, hyperlinks 1124, model identification parameters 1126, configuration parameters 1128, master-slave detection logic or signals, diagnostics logic or results 1134, log data 1136, device identifiers (e.g., serial numbers, MAC addresses, etc.), or any other type of information used by actuator 1100 and/or stored in memory 1108. Processing circuit 1104 may retrieve data from memory 1108 and transmit the retrieved data to the external device via wireless transceiver 1112. Processing circuit 1104 may receive data from the external device via wireless transceiver 1112 and store the received data in memory 1108.

Wireless transceiver 1112 may utilize any of a variety of wireless technologies and/or communications protocols for wireless data communications. For example, wireless transceiver 1112 may use near field communications (NFC), Bluetooth, Bluetooth low energy (BLE), WiFi, WiFi direct, radio frequency communication (e.g., RFID, radio waves, etc.), optical communication, electromagnetic signals, sound transmission, or any other wireless communications technology.

Wireless transceiver 1112 may be configured to operate in a powered mode or a non-powered mode. In the powered mode, wireless transceiver 1112 may receive power from another energy source (e.g., a wired power connection, a battery, etc.). In the non-powered mode, wireless transceiver 1112 may draw power from an electromagnetic field, wave, or radiation using an antenna or receptor. Wireless transceiver 1112 may use any of a variety of wireless energy transfer technologies (e.g., electrodynamic induction, electrostatic induction, lasers, microwaves, etc.) to obtain or harvest energy wirelessly. Advantageously, wireless transceiver 1112 allows actuator 1100 to engage in bidirectional wireless data communications without requiring a wired power or data connection to an external device.

Still referring to FIG. 11, actuator 1100 is shown to include a wired communications interface 1114. In some embodiments, actuator 1100 uses wired communications interface 1114 to communicate with a controller (e.g., controller 100, described with reference to FIGS. 2-6), another actuator, or to an external system or device. In other embodiments, actuator 1100 uses wireless transceiver 1112 for such communications.

Wired communications interface 1114 is shown to include an input data connection 1116 and a feedback data connection 1118. If actuator 1100 is arranged as a master actuator, input data connection 1116 may be connected to the output of a controller and feedback data connection 1118 may be connected to the input connection of another actuator. If actuator 1100 is arranged as a slave actuator, input data connection 1116 may be connected to the feedback data connection of another actuator and feedback data connection 1118 may be connected to the input of the controller or may not be connected to anything. Wired communications interface 1114 may allow actuator 1100 to function as any of actuators 54-58, 88-90, or 102-106, as described with reference to FIGS. 2-6.

Referring now to FIG. 12, a flowchart of a process for wirelessly configuring and communicating with an actuator in a HVAC system is shown, according to an exemplary embodiment. In some embodiments, process 1200 is performed by actuator 1100, as described with reference to FIG. 11.

Process 1200 is shown to include drawing power from a wireless signal received at a wireless transceiver of an actuator (step 1202). Step 1202 may include drawing power from an electromagnetic field, wave, or radiation using an antenna or receptor. Step 1202 may include using any of a variety of wireless energy transfer technologies (e.g., electrodynamic induction, electrostatic induction, lasers, microwaves, etc.) to obtain or harvest energy wirelessly.

Process 1200 is shown to include using the power drawn from the wireless signal to power a processing circuit of the actuator (step 1204). The power drawn from the wireless signal may be stored in one or more capacitors within the actuator and may be used to power the processing circuit and/or the wireless transceiver. Advantageously, this allows the actuator to engage in bidirectional wireless data communications without requiring a wired power or data connection to an external device.

Process 1200 is shown to include transmitting data stored in a memory of the actuator to an external device via the wireless transceiver (step 1206) and receiving data from the external device via the wireless transceiver (step 1208). In some embodiments, process 1200 may include only one of steps 1206 and step 1208. For example, the actuator may transmit data stored in the memory of the actuator to the external device without receiving data from the external device. Alternatively, the actuator may receive data from the external device without transmitting data stored in the memory of the actuator. One or both of steps 1206 and 1208 may be performed in various implementations.

Data communicated via the wireless transceiver may include firmware data 1120, control logic data 1122, hyperlinks 1124, model identification parameters 1126, configuration parameters 1128, master-slave detection logic or signals, diagnostics logic or results 1134, log data 1136, device identifiers (e.g., serial numbers, MAC addresses, etc.), or any other type of information used by the actuator and/or stored in the memory of the actuator.

Process 1200 is shown to include storing the data received from the external device in the memory of the actuator (step 1210). Step 1210 may be performed in response to receiving data from the external device via the wireless transceiver. The data received from the wireless transceiver may replace existing data stored in the memory of the actuator or may be stored in free space within the memory of the actuator. For example, the actuator may be constructed and packaged as a generic actuator (e.g., without firmware data, control logic, and/or configuration parameters) and subsequently configured with suitable firmware, software, configuration parameters, or other data specific to a particular actuator model and/or implementation.

Configuration of Exemplary Embodiments

Embodiments of the subject matter and the operations described in this specification can be implemented in digital electronic circuitry, or in computer software embodied on a tangible medium, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Embodiments of the subject matter described in this specification can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on one or more computer storage medium for execution by, or to control the operation of, data processing apparatus. Alternatively or in addition, the program instructions can be encoded on an artificially-generated propagated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus. A computer storage medium can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them. Moreover, while a computer storage medium is not a propagated signal, a computer storage medium can be a source or destination of computer program instructions encoded in an artificially-generated propagated signal. The computer storage medium can also be, or be included in, one or more separate components or media (e.g., multiple CDs, disks, or other storage devices). Accordingly, the computer storage medium may be tangible and non-transitory.

The operations described in this specification can be implemented as operations performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources.

The term “client or “server” include all kinds of apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, a system on a chip, or multiple ones, or combinations, of the foregoing. The apparatus can include special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). The apparatus can also include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, a cross-platform runtime environment, a virtual machine, or a combination of one or more of them. The apparatus and execution environment can realize various different computing model infrastructures, such as web services, distributed computing and grid computing infrastructures.

A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub-programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform actions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for performing actions in accordance with instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a Global Positioning System (GPS) receiver, or a portable storage device (e.g., a universal serial bus (USB) flash drive), to name just a few. Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

To provide for interaction with a user, embodiments of the subject matter described in this specification can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube), LCD (liquid crystal display), OLED (organic light emitting diode), TFT (thin-film transistor), plasma, other flexible configuration, or any other monitor for displaying information to the user and a keyboard, a pointing device, e.g., a mouse, trackball, etc., or a touch screen, touch pad, etc., by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. In addition, a computer can interact with a user by sending documents to and receiving documents from a device that is used by the user; for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser.

Embodiments of the subject matter described in this specification can be implemented in a computing system that includes a back-end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front-end component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an embodiment of the subject matter described in this specification, or any combination of one or more such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), an inter-network (e.g., the Internet), and peer-to-peer networks (e.g., ad hoc peer-to-peer networks).

While this specification contains many specific embodiment details, these should not be construed as limitations on the scope of any inventions or of what may be claimed, but rather as descriptions of features specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product embodied on a tangible medium or packaged into multiple such software products.

Thus, particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain embodiments, multitasking and parallel processing may be advantageous.

The background section is intended to provide a background or context to the invention recited in the claims. The description in the background section may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in the background section is not prior art to the description or claims and is not admitted to be prior art by inclusion in the background section. 

What is claimed is:
 1. An actuator in a HVAC system, the actuator comprising: a mechanical transducer; an input data connection; a feedback data connection; and a processing circuit configured to use a master-slave detection signal communicated via the feedback data connection to select an operating mode for the actuator from a set of multiple potential operating modes comprising a master operating mode and a slave operating mode; wherein the processing circuit is configured to operate the mechanical transducer in response to a control signal received via the input data connection according to the selected operating mode.
 2. The actuator of claim 1, wherein the processing circuit is configured to generate the master-slave detection signal and to output the master-slave detection signal via the feedback data connection.
 3. The actuator of claim 2, wherein the processing circuit is configured to monitor the feedback data connection for a reply signal from another actuator, wherein the reply signal is generated by the other actuator in response to receiving the output master-slave detection signal; wherein the processing circuit is configured to select the master operating mode in response to detecting the reply signal from the other actuator at the feedback data connection.
 4. The actuator of claim 1, wherein the processing circuit is configured to monitor the input data connection for the master-slave detection signal, wherein the master-slave detection signal is generated by another actuator; wherein the processing circuit is configured to select the slave operating mode in response to detecting the master-slave detection signal from the other actuator at the input data connection.
 5. The actuator of claim 4, wherein the processing circuit is configured to generate a reply signal in response to detecting the master-slave detection signal at the input data connection; wherein the processing circuit is configured to output the reply signal via the input data connection.
 6. The actuator of claim 1, wherein the processing circuit is configured to monitor the input data connection for the master-slave detection signal and to monitor the feedback data connection for a reply signal; wherein the processing circuit is configured to select a normal operating mode in response to a determination that the master-slave detection signal is not detected at the input data connection and the reply signal is not detected at the feedback data connection.
 7. The actuator of claim 1, wherein the processing circuit is configured to engage in bi-directional communications with another actuator via the feedback data connection; wherein the feedback data connection is connected with an input data connection of the other actuator.
 8. The actuator of claim 1, wherein the processing circuit is configured to engage in bi-directional communications with another actuator via the input data connection; wherein the input data connection is connected with a feedback data connection of the other actuator.
 9. The actuator of claim 1, further comprising: memory storing instructions for generating the master-slave detection signal; wherein the processing circuit generates the master-slave detection signal according to the stored instructions.
 10. The actuator of claim 1, wherein the master-slave detection signal comprises a series of digital pulses.
 11. The actuator of claim 1, wherein the processing circuit comprises: a master detection circuit configured to monitor the input data connection for the master-slave detection signal, to generate a reply signal in response to detecting the master-slave detection signal at the input data connection, and to output the reply signal via the input data connection; and a slave detection circuit configured to generate the master-slave detection signal, to output the master-slave detection signal via the feedback data connection, and to monitor the feedback data connection for the reply signal. 